Experimental investigation of formability and surface quality of tinplate sheets in the single-point incremental forming process

This study investigated the mechanical behavior of thin tin-coated steel sheets (tinplate) when subjected to the Single-Point Incremental Forming (SPIF) process.Tensile tests were performed at 0°, 45°, and 90° with respect to the rolling direction to determine the anisotropic behavior of the material.SPIF tests were carried out using hemispherical tools with radii of 2.5 mm, 5.0 mm, 7.5 mm, and 10 mm.For each tool, the maximum forming angle was experimentally determined through an iterative approach while maintaining a constant target surface roughness.The results show that smaller tool radii lead to higher forming angles (up to 54°), although they require longer forming times.The limiting strains considerably exceeded those obtained in the uniaxial tensile test, with the maximum strain reaching 52%.The thickness reduction was consistent with the strain measurements, and surface roughness was evaluated using microscopy.The study highlighted the influence of tool geometry on formability, surface quality, and final geometry, providing insights for optimizing SPIF parameters in tinplate sheet applications.